Ferris IS600 Series Operator's Manual page 37

Inspecting the Mower Blades
DANGER
Thrown objects hazard
Avoid injury: a worn or damaged mower blade can break
and a piece of the blade could be thrown into the operator's
area or bystander's area resulting in serious personal injury
or death.
• Inspect the mower blade every 25 hours or at least
once per year.
• If the mower blade hits a solid object, stop the engine
immediately and inspect the mower blades.
• Never weld or straighten bent mower blades.
1. Remove the mower blade from the unit. See Removing
the Mower Blades.
2. Inspect the mower blade (Figures 48 and 49). Discard the
mower blade if it has any of the following conditions:
• More than .5" (12,7 mm) of the mower blade metal
has been removed from previous sharpening or wear
(A, Figure 48)
• The air lifts are excessively eroded (A, Figure 49) and
the notch (B) is .25" (6,35 mm) deep or greater.
• The mower blade is broken or bent.
48
49
3. If the cutting edges are not sharp or have nicks, sharpen
the blades. See Sharpening the Mower Blades.
Sharpening the Mower Blades
WARNING
Thrown objects and fire hazard
Grinding mower blades throws sparks and fine metal
particles that are capable of igniting gasoline and gasoline
vapors, and that can injure unprotected eyes.
Be sure all flammable materials are cleared from the area
where grinding will occur.
Always wear safety glasses or goggles when grinding
mower blades.
1. Sharpen mower blades with a grinder, hand file, or
electric blade sharpener.
2. Sharpen the blade by removing an equal amount of
material from the cutting edge of each end of the blade.
3. Keep the original bevel (A, Figure 50) when grinding. DO
NOT change the mower blade bevel.
50
4. The mower blade should have a maximum of 1/64" (0,40
mm) cutting edge (B) or less.
Balancing the Mower Blades
CAUTION
Thrown objects hazard
An unbalanced mower blade can create excessive vibration
and damage the unit, or cause mower blade failure resulting
in thrown debris.
Be sure blade is balanced before installing.
1. Clean the mower blade to remove any dried grass or
other debris.
2. Clamp a nail in a bench vise, hang the mower blade
on the nail, and position the blade in a level horizontal
position as shown in Figure 51.
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